Refrigerating apparatus



June 6, =1939. A. A. KucHl-:R 2,161,421

l REFRIGERATING APPARATUS Filed D80. 29, 1954 mi f4 `BY #wwwa ATTORNEY.

Patented June 6, 1939 REFRIGERATIN G APPARATUS Andrew A. Kucher, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application December 29, 1934, Serial No. 759,760

12 Claims.

This invention relates to refrigerating apparatus and more particularly to a novel system and control therefor for automatically varying the refrigeration output of the apparatus.

Heretofore in the construction of refrigerators,

' particularly those comprising a cabinet having a food storage compartment and which are intended principally for household usein meeting the problem of varying the refrigeration output of l the machine to provide substantially constant food preserving temperatures inthe cabinet, it has been customary to provide an automatic switch for stopping and starting the refrigerant liquefying unit as by controlling the motor which drives the compressor and to thus operate the apparatus intermittently. With such a method of control, the system, while it is operating, produces refrigeration at a substantially constant rate and the variation in average amount of refrigerant lo produced over agiven period results in variations in the lengths of the period during which the machine operates or is idle. A refrigerating apparatus of this character has certain disadvantages, among them being high flrst cost and frequent service diiliculties, together with certain difficulties arising'from the continued stopping and starting of the refrigerant liquefylng unit, particularly with liquefying units of the compression type. v

It is an object, therefore, of the present invention to provide a refrigerating apparatus which 'is' readily adapted to extremely low cost produc-4 tion and inv which the dimculties inherent in `an intermittently operated refrigerator" are avoided.

It is a further object of the invention to provide a refrigerating apparatus in which automatic control of the output of the apparatus is attained while the refrigerant liquefyingunit is constantly running.

It is also an object of the invention to provide a refrigerating apparatus in which the liquefying unit runs continuously throughout a substantial range of room temperatures normally encountered and in which substantially constant temperatures 5 are maintained in the food preserving or other compartment to be cooled solely by purposely causing the refrigerating system to operate at reduced efficiencies when its full capacity is not required.

50 Another object is to provide a refrigerating apparatus in which'the food compartment is ventilated and to provide automatic means for controlling the ventilation in the food compartment.

Further objects and advantages of the present 55 invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention` is clearly shown. V In the drawing:`

Referring now to the drawing, the ligure illustrates a vertical cross section of a refrigerator cabinet embodying one form of the present invention.

In the form of the invention illustrated in the ligure there is provided a refrigerator cabinet generally designated as I0 having a food compartment. l2 ,in which substantially constant temperatures are to be maintained throughout a wide range of room temperatures. For example, in

an ordinary household refrigerator, it is desirable to maintain a temperature within the compartment I2 between substantially 42 and 50 F., while room temperatures may run as high as 110 F., and are generally. not below 60 F. Associate' with the cabinet I0 is a refrigerant liquefying unit comprising a compressor il, and a condenser I6, both of which may take any of numerous suitable forms in order to maintain a constant supply of liquefied refrigerant for use in the system. Within the compartment I2, there is mounted a refrigerant evaporator Il for cooling the air within the compartment I2, and which may also be provided with means for freezing water as is well known in the art. Suitable means for controlling the ow of liquid refrigerant from the liquefying'unit to the evaporator are provided and may comprise a fixed restrictor or other refrigerant control device 20. 'I'he elements so far described are connected in series by suitable refrigerant conduits in the well known manner to provide a closed refrigerant circuit.V The elements of the refrigerating system including the refrigerant liquefying unit, the liquid refrigerant control device and the evaporator are preferably so proportioned and cooro dinated with each other as to provide a maximum refrigeration output not substantially in excess of the heat load requirements of the cabinet under the highest room temperature normally encountered.

In order to provide for a reduction in the out- 4 put of the refrigerating system under conditions at which its maximum output is not required, means are provided for purposely causing the system to operate at reduced eiciency. Generally speaking, this means has for its purpose the introduction of warm air into the foodcompartment of the refrigerator cabinetwhenever the temperature therein becomes toolow. In addition, the invention provides for removing the in an opening 22 is formed at the lower portion of a side wall of the food compartment I2 and immediately beneath the condenser I6. A closure member ordoor 24 is provided for controlling the passage of air through the opening 22 and in order to automatically operate the door -24 in accordance with temperature conditions within the compartment I2, a thermostatic bellows 26 is mounted in thecompartment I2 by means of a bracket 28. The movable end of the bellows 26 is connected to the door 24 through a bell crank 29 in a manner to open the door when' the temperature within the compartment I2 goes below the minimum desired temperature. One or more openings 30 are provided preferably near the top of the food compartment I2 for permitting the ingress of warm air to the compartment I2 whenever cold air is discharged therefrom through the `opening 22. In the embodiment il.

lustrated, a flue 32 surrounds the condenser I6 and the door 24 in order to properly direct the circulation of air over the condenser, I6. The openings 30 are situated near the top of the flue 32 so that the warm air taken into the cabinet may be withdrawn from the stream of air which passes over the condenser.

In operation, expanded refrigerant is withdrawn from the evaporator I8 by the compressor I4 and compressed and delivered to the condenser I6 where the refrigerant liqueles by giving up heat to the air passing through the flue 32. Liqueed refrigerantis fed from the condenser to the liquid refrigerant control device 20, where it expands into the evaporator to be vaporized and to withdraw heat from the air in the compartment I2. Under conditions when the maximum output ofthe refrigerating system is not required to maintain proper temperatures in the compartment I2, that is when the evaporator I8 brings the temperature ofthe air in the compartment I2 down to the lower limit of the desired temperature range, the bellows 26 expands, opening the door 24. 'I'his permits cold air to be drawn through the opening 22 and up the flue 32 and at the same time warm air enters the compartment I2 through they opening 30. As soon as the temperature within the compartment I2 has been sufficiently raised, the bellows 26 will again expand, closing the door 24. In this manner, the temperature of the air within the compartment: I2 is maintained substantially constant, even under conditions such that the capacity of the refrigerating system is greater than necessary to handle the heat load of the compartment 12. It will be noted that the refrigerant liquefying unit is maintained in continuous operation and that the temperature of the air in compartment I2 is maintained substantially constant notwithstanding the continuous operation of the refrigerant liquefying unit. By this construction, it 'is Apossible to provide a refrigerating apparatus `.t5/herein the refrigerant llitluefying unit runs continuously throughout substantially the entire range of room temperatures normally encountered, although if a thermostatic switch is provided for controlling the motor-compressor I4, its cut-out point may be selected so as to provide intermittent operation of the liquefying unit below any desired room temperature less than maximum.

Thus, the present invention provides a refrigerating apparatus having means for maintaining the temperature of the compartment to be cooled within a predetermined range, while the refrigerating apparatus vfor the compartment is maintained in continuous operation.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A refrigerating apparatus comprising in combination a cabinet to be cooled, refrigerant liquefying means, and a refrigerant evaporator, coordinated with each other to providel a capacity not substantially in excess of the heat load of the cabinet under the highestroom temperature normally encountered, and means for regulating cabinety temperatures by an interchange of heat between the evaporating refrigerant and the liquefying refrigerant,

2. A refrigerating apparatus comprising in combination a cabinet to be cooled, refrigerant liquefying means, and a refrigerant evaporator, and means for regulating cabinet temperatures by an interchange of heat between the evaporating refrigerant andthe liquefying refrigerant.

3. A refrigerating apparatus comprising in combination a cabinet to be cooled, refrigerant liquefying means, and a refrigerant evaporator, coordinated with each other to provide a capaci` ty not substantially in excess of the heat load of the cabinet under the highest room temperature normally encountered, and means for regulating cabinet temperatures by the -introduction o-f warm air-to the `cabinet to displace a portion of the `cold air therein.

4. A refrigerating apparatusV comprising in combination a `cabinet to be cooled, refrigerant liquefying means, and a refrigerant evaporator, coordinated with each other to provide a capacity not substantially in excess of the heat load of the cabinet under\the highest room temperature normally encountered, and meansvr responsive to cabinet temperature conditions for controlling air circulation between the interior and exterior of the cabinet.

5. A refrigerating apparatus comprising in combination a cabinet to be cooled, refrigerant liquefying means, and a refrigerant evaporator, coordinated with each other to provide a capacity not substantially in excess of the heat load of the cabinet under the highest room temperature normally encountered and temperature responsive means for controlling ventilation of the cabinet.

6. A refri'gerating apparatus comprising in combination a cabinet to be cooled, refrigerant liquefying means, and a refrigerant evaporator,

coordinated with each other to provide a capacity not substantially in excess of the heat load of the cabinet under the highest room temperature normally encountered, and means for regulating y cabinet temperatures by an interchange of heat between the evaporating refrigerant and the liquefying refrigerant, said last mentioned means including a thermostatically controlledclosure device near the bottom of the cabinet for permitting cold air from the cabinet to pass out of the same and over at least a' portion of the liquefying means.

"I. A refrigerator provided with-a heat insulated cooling compartment, a refrigeratlng machine for continuously abstracting heat from said cooling compartment,means for intermittently admitting fresh air to said coolingcom'partment in accordance with a psychrometric function of the air within said compartment, and means utilizing heat generated by said refrigerating machine for inducing a flow of air from said cooling compartment. 8. A refrigerator provided with a heat insulated cooling compartment, a refrigerating machine including a refrigerant evaporator located in said cooling compartment and a continuously operating refrigerant circulatory unit located outside said cooling compartment, temperature responsive means for intermittently admitting fresh air to said coolingv compartment, and means utilizing heat generated by said refrigerant circulatory unit for inducing a flow of air from said cooling compartment.

9. A refrigerator provided with a heat insulated cooling compartment, a refrigerating machine for abstracting heat from said cooling compartment, means for intermittently admitting fresh air to said cooling compartment lin accordance with a psychrometric function of the air within said compartment, and means utilizing heat generated by said refrigerating machine for inducing a flow of air fromsaid cooling compartment.

10. A refrigerator provided with a heat insulated cooling compartment, a refrigerating machine including a refrigerant evaporator located in said cooling compartment anda refrigerant circulatory unit located outside said cooling compartment, temperature responsive means for intermittently admitting 'fresh air to said cooling compartment, and means utilizing heat generated by said refrigerant circulatory unit for lnducing a flow of air from saidf'cooling compartment.

11. A refrigerator provided with a heat insulated cooling compartment, a refrigerating machine including a refrigerant evaporator located in said cooling compartment and a continuously operating refrigerant circulatory unit located outside said cooling compartment, means for intermittently admitting fresh air to said cooling compartment, and means utilizing heat generated by said refrigerant circulatory unit for inducing a flow of air from said cooling compartment.

12. A refrigerator provided with a heat insulated cooling compartment, a refrigerating machine including a refrigerant evaporator located in said cooling compartment and a continuously operating refrigerant circulatory unit located outside said cooling compartment, temperature responsive means for admitting fresh air to said cooling compartment, and means utilizing heat generatedby said refrigerant circulatory unit for inducing av flow of air from said cooling compartment.l Y ANDREW A. KUCHER. 

